1. Field of the Invention
The embodiments of the invention disclosed herein relate to a pleasure watercraft having plural hulls with narrow surface wave-generating cross sections to reduce the friction drag and to reduce the forward bow wave, and having streamlined submerged flotation devices to provide buoyancy.
2. Description of the Related Art
An electrically powered pleasure watercraft is a desirable alternative to a watercraft powered by an internal combustion engine for many applications. For example, electrical motors are quiet, economical, and nonpolluting. Thus, an electrically powered watercraft may be used in places (e.g., small restricted waterways, such as private lakes) and at times (e.g., at night or early morning) when a watercraft with conventional fuel-burning engines cannot be used.
On the other hand, an electrically powered pleasure watercraft tends to be slower than a conventionally powered watercraft of the same size because of limitations on the size and weight of the electrical motors and storage batteries that can be installed in a small hull. Furthermore, unlike an electrically powered commercial watercraft or a military watercraft, which has a fuel-powered generator to provide current to charge the batteries or to operate the electrical motors directly, an electrically powered pleasure watercraft usually does not have an on-board generator to maintain the charge of the batteries. Thus, the range of the electrically powered watercraft is limited by the capacity of the batteries (e.g., the amount of charge that can be supplied to the batteries when the batteries are charged while the watercraft is docked).
The limited range of an electrically powered pleasure watercraft reduces the utility of the watercraft, particularly with respect to large waterways or recreational areas with limited docking and recharging facilities. For example, the batteries are quite heavy and difficult to install and remove. Thus, if an electrically powered watercraft depletes the energy in the batteries during a cruise, a potential rescuer cannot easily provide an emergency supply of “fuel” to enable the watercraft to return to shore to be recharged. Most likely, the watercraft must be towed to shore to be recharged.
Because of the combination of low speed and limited range, electrically powered pleasure watercraft are generally used for sightseeing and picnicking cruises in protected harbors and other small waterways. Such watercraft are generally not desirable for extended cruises of long duration or at significant distances from docking/recharging facilities. Thus, a need exists for an electrically powered watercraft with an extended cruise range.